Mill for grinding.



. No. 721,984. PATENTED MAR. 3,1903.

J; a. WEGBRIFP MILL FOR GRINDING.

APPLIOATIOF FILED 1mm 7. 1902. no MODEL. 3 SHEETS-SHEET 1;

F/GJ

No. 721,984. PATENTED MAR. 3. 1903. J. G. WEGERIF.

MILL FOR GRINDING.

APPLIGATION FILED JUNE 7, 1902. vNO MODEL. 3 SHEETS-SHEET 2.

WIT/76.95155 Lu mew/V702? TNE Norms Pzrzas cc. Prism-Limo; WASHXNGTON, n, c.

UNITED STATES TOHANNES CHRISTIAAN WVEGERIF,

or BATTLESBRIDGE, ENGLAND, AS-

SIGNOR TO THE RENFREW CRUSHER COMPANY, LIMITED, OF LON- DON, ENGLAND.

' MILL FOR GRINDING.

SPECIFICATION forming part of Letters Patent No. 721,984, dated March 3, 1903.

Application filed June "7, 1902.

To all whom it may concern.-

Be it known that 1,.J OHANNES OHRIsTIAAN WEGERIF, engineer, a subject of the Queen of the Netherlands, residing at Rawreth Rectory, Battlesbridge, in the county of Essex, England, have invented new and useful Improvements in Mills for Grinding,,of which the following is a specification.

My invention relates to pan-and-roller mills, and has for its object to supplement the crushing action due to the more weight of the roll by a powerful tearing action, whereby the efficiency of the mill is greatly increased. The tearing action thus exerted on the particles to be ground is obtained as the effect of the conjoint action of causing both the pan and the grinding-rolls to be positively driven, so that their surfaces in contact run in similar directions, and of setting each grinding-roll permanently skewwise with regard to the direction of rotation of the pan, so that the roll will at any point of contact of its grindingsurface with the pan necessarily move in a plane diverging from the path followed by the corresponding point of the pan. The result of this positive driving andrelative arrangement of the roll and pan is that in addition to the usual crushing stress the particles are subjected to a tensile stress, tending to tear the individual particles asunder, the tearing action thus coacting with the crushing action to produce the disruption of the particles.

Reference is to be had to the accompanying drawings, wherein- Figure 1 is a plan, and Fig. 2 is an elevation, showing in a somewhat elementary form the improved pan-and-roller mill, only two of the four rolls shown in Fig. 1 being illustrated in Fig. 2. It is, however, to be understood that any number of rolls may be used from one upward. Fig. 3 is a part detail section on line 3 3, Fig.1, drawn to a larger scale; and Fig. 4: is a similar section of the pan-bottom and adjacent parts, showing a modification.

The mill comprises a revolving pan A of annular form and of trough-like section, as shown in Fig. 3, mounted to revolve on antifriction-bearings, and grinding-rolls or edgerunners B, mounted on shafts O, which are Serial No. 110,633. (No model.)

not radial to the axis of revolution of the pan, as in ordinary pan-and-roller mills, but, as represented by their center lines o in Fig. 1, are tangential to a circle-such as c, for instanceconcentric'with the pan-axis a. The planes of revolution of the several rollsB will therefore not be tangential to a circle concentric with the'axis of the pan ,as usual,so that the plane at which any point of contact of a roll with the pan moves will intersect the circle described by the corresponding point of contact of the pan with the roll, with the. result that what may be termed a cross-grinding action, as well as the usual crushing action,

will be produced.

The shaft 0 of each roll B is mounted in a lever-frame D, each lever D having its fulcrum din a bearing in an overhead frame E, supported by the base-frame F of the mill and bolted to a central pillar G. Each lever D is preferably in the form of an elbow-lever, the roller-shaft 0 being journaled at the elbow and the lever D being forked, as shown in plan, so as to afiord a double bearing for the shaft 0. The forked limbs converge to a single point in the central plane of the roll B, to which point is applied the elastic or yielding pressure of springs H, or it might be of a weight. This end of the leverD is grooved to engage with a vertical guide-rod h, on which the springs H are confined, and the downward movement of the lever D is limited by adjustable stops I, so as to regulate the minimum distance between the grinding-surface J of the pan and the periphery of the roll B.

The shaft 0 of each grinding-roll B is pro vided with a belt-pulley K, by which the roll is driven, or the rolls might be driven by toothed gearing, provision being made for the slight vertical play of the rolls, both the rolls of the pan being positively driven, so that their contacting surfaces move in similar but divergent directions.

The annular pan A may for convenience be constructed in segments bolted together and is connected by radial arms with a central hub A, fitted to rotate about a bearing 9 on the central pillar G. The pan may be supported upon antifriction-rollers L, mounted on the base-frame F and arranged, preferably, in

sets of three, situated beneath the points of operation of the several rolls 13, other single rollers L being arranged at intermediate points. These antifriction-rollers are provided with end gudgeons Z, which are mounted in suitable bearings Z in the base-frame F, or instead of antifriction-rollers bearing-balls L Fig. 4, running in annular grooves or races Z between the pan A and base-frame F, may be used. The frame of the pan is provided at the underside with a ring M of teeth gearing with a toothed wheel N, fast on a drivingshaft 0, extending diametrically beneath the pan.

The grinding part J of the pan may be made in segments and hasa base of dovetailed form, as shown in Figs. 3 and 4:, fixed in position in a corresponding dovetailed groove in the bed of the pan by packings J of metal run into the groove and calked, if necessary.

The sides a a of the annular trough-like pan A are preferably flared, as shown, particularly the outer one a, so as to keep clear of the rolls B, and they are extended upward to a sufficient height to prevent splashing over by panels P, Fig. 3, slipped into grooved standards Q, Figs. 1 and 3, fixed upon the sides of the pan proper. These panels P (which are omitted in Fig. 2) would be formed of perforated sheet metal stiifened by marginal flanges and covered, if necessary, with suitable straining fabric. The pan may be provided at its inner circumference with an annular receiving-trough B, into which the water holding the ground matters in suspension after passing through the mesh of the strainers may overflow and whence it is discharged through outlets 1' into a stationary receiving-trough beneath, (not shown,) from which it is conducted away by suitable means.

I claim 1. A pan-and-roller mill wherein both the pan and the rolls are driven positively so that their contacting surfaces move in the same direction and wherein the rolls are permanently set skewwise in the pan with their axes permanently parallel to the surface of the pan and non-radial to the axis of the pan so that a disruptive or tearing action will be produced as well as a crushing action, substantially as specified.

2. A pan-and-roller mill wherein both the pan and the rolls are driven positively so that their contacting surfaces move in the same direction and wherein the rolls are permanently set skewwise in the pan with their axes JOllANNES CHRISTIAAN \VEGERII. Witnesses:

T. S. OSMAN, WALTER J. SKERTEN. 

